I. Field of the Invention
The invention relates to a connection unit for a releasable quick coupling for connection to an end of a metal pipeline, said end being expanded step-wise.
II. Reference to the Prior Art
Prior art quick couplings of the type disclosed by the present invention are shown in: EP 0 806 597 that issued Nov. 12, 1997 for a Quick Acting Coupling; WO 95/10002 that issued Apr. 13, 1995 for a Quick Connect Stuffer Pin; DE 197 22 842 A that concerns a detachable rapid-action coupling device, and; DE 43 00 037 that concerns a Releasable Socket Coupling Device for Pipe.
A connection unit according to the present invention includes a cylindrical housing head with a receiving area for the insertion of a tubular inserting part that is provided with an encircling retaining rib at a distance from the end of the pipe.
The connection unit furthermore includes a separate retaining element with elastically expandable detent edges directed radially into the receiving area to catch behind the retaining rib after the insertion of the inserting part as well as a connecting sleeve formed on the housing head, said connecting sleeve being inserted into the expanding end of the metal pipeline and being anchored there together with sealing rings lying sealingly on the inserting part.
In this case the inserting part can be the end of a stable metal pipe which, for example, is used for fuel lines. It can however also consist of rigid or hard elastic plastic or other customary injection molding material which can be connected according to the prior art via a connecting conduit to a tube or pipeline (DE 43 00 037 C1).
A connection unit of this type is used in the case of a quick coupling formed in two parts and still not belonging to the state of the art (DE Application 197 22 842) in order to form the receiving housing rotatably with respect to the base body. The head part provided with the separate retaining element in this case also has a connecting sleeve which can be inserted and anchored in the tubular insertion area of the base body with its sealing rings forward, where the insertion of the sealing rings is associated with an additional mounting expenditure. In the case of this coupling, the base body, precisely like the corresponding head part, is made of plastic and is provided at its inserted end with a pipe conduit for connection to a tube line. The rotatability between the head part and base body alone is the sense and goal of the bipartite quick coupling.
It is the objective of the present invention to form the connection unit so that it, together with the sealing rings, can be connected to the end of pipe and fixedly anchored to it.
For the realization of the objective set, at least one expandable detent is formed on the housing head of the connection unit for locking the radially outwardly bent edge of the metal pipeline and at least one sealing ring can be positioned in front of the frontal side of the connecting sleeve by means of a supporting sleeve. Preferably, upon insertion of the connection unit into the expanded end of the pipeline, the support sleeve to slides forward, over the connecting sleeve, toward housing head while the connecting sleeve simultaneously urges the sealing ring into the end of said pipeline.
By the measures according to the invention it is achieved in a simple manner that on assembly of the quick coupling the sealing rings can be mounted together with the connection unit and the connecting sleeve can simultaneously be anchored and centered in the end of the pipe.